Mixing device



June 24, 1958 l o 2,840,358

MIXING DEVICE Filed May 24, 1957 unnm n INVENTOR. ANTHONY Aer/N0 F54/M4%MJ4 This invention relates to agitating devices and particu larly toa rotating stirrer" for viscous or semi-solid materials.

Condu'cive to a better understanding of theinvention it may be well topoint out that it is' common practice to use motor driven stirringdevices, having a plurality of spaced parallel discs secured to a rotaryshaft. The spinning discs are supposed to suck the liquid to be mixedinward and then throw it outward due to the action of the spinning edgesof the discs. 9

However in the mixing of viscous liquid such as heavy petroleumproducts, greases, tars, soaps, etc., a great A collar"13.i s welded tothe shaft 11 immediately above its thre'adejd end' .29. And a lower bar14 is swivelly motiuitedbn"the shaft 11, againstthe lower face of the'collar l3. The bar 14 is held in place by a nut 30. The bar 14 also hastwo holes 17 and 18, similarly countersunk as those of the upper-bar 12,and similarly spaced. The two bars 12 and 14 act as a yoke to supporttwo, headed impeller shafts 19 and 20 which are mounted in the holes 15,17 and116, 18, respectively. Each shaft 19 and has a threaded lower endand a semi-spherical head'21, and 22, respectively, adapted to seat intheholes 4 and 16,.respectively, of the upper bar 12. The shaftsfrictional drag is exerted by the viscous materials on the their centerof revolution, whereby intersecting fluid flow.

lines are created which act to reduce all vortex forming forces to aminimum. a

Another object is to provide a device of the type stated whose discs arefree to rotate on their axes, so as to afford minimal frictionalopposition to the movement of fluid passing therebetween.

A further object is to provide a device of the type stated that iscapable of functioning effectively in liquids of any viscosity, and evenin semi-solids.

These and other objects of the invention will become Furthermore, withsuch viscous liquids the inter-,

apparent from a reading of the following specification v and claims,together with the accompanying drawing, wherein:

Figure lis a perspective view of a mixing device made in accordance withmy invention;

Figure 2 is a side elevation of the same;

Figure 3 is an exploded view of the device;

Figure 4 is a side elevation of an alternate form of the device havingconically shaped discs: and

Figure 5 is a top plan view of one of the conical'discs.

Referring more particularly to the drawing there is seen the mixer headthat is the subject of this invention broadly indicated by referencenumeral 10.

The device comprises a driver shaft 11, adapted to be connected directlyat its upper end to a driving motor, not illustrated, or to a flexiblemotor driven shaft.

The bottom end 29 of the shaft 11 is threaded, as seen in Figure 3. 1 V

A flat bar 12 is welded to the shaft 11. The bar 12 has two spaced holes15 and 16, at the ends thereof. Each hole is countersunk at the top andbottom to form a semicircular seat.

19 and 20 are held in place by means of nuts 25 and 26 which bearagainst semi-spherical washers 23 and- 24 which are seated in holes 17and 18,-respectively, of the lower bar 14.

Reference numerals 27 indicate a plurality of flat discs which areco-axially mounted on .the impeller shafts 19 and are-spaced apart inparallel relation by collars 28;. 'Boththe discs 27 and the collars 28are free to rotate on impeller shafts 19 and 20.

In assembling the mixer head 10, the lower yoke bar 14 is swivelled withrelation to the upper yoke bar 12 until the two impeller shafts 19 and20 assume the angular inclination to each other and the shaft 11, asillustrated in Figures 1 and 2. The nut 30 is then tightened, as are thenuts 25 and 26, thus locking the various elements together into a rigidstructure. 7

In operation, it will be evident that upon rotation of the shaft 11, thetwo impeller shafts 19 and 20 together with their co-axially supporteddiscs 27 will revolve about the shaft 11 in a plane angularly inclinedto its center of rotation. At the same time the several discs 27 arefree to rotate on their own axes, that is the longitudinal axes of theimpeller shafts 19 and 20, upon which they are mounted. a 1

When the device 10 is immersed in a viscous fluid it will be evidentthat the spaced and parallel discs 27 on each impeller shaft 19 and 20will cut angularly opposed paths through the mixture, whereby all flowlines of the mixture created by one set of discs will run counter tothose created by the other set of discs. These opposing flow lineseffectively counteract any tendency for a vortex to be formed, therebyrendering the mixing action more efficient than that attainable with anyprior art devices.

Furthermore it will be apparent that any frictional drag between thedisc surfaces and the fluid being mixed will cause the discs to rotatefreely on their axes, thus facilitating the break-up and mixing actionof the discs, since their rotation acts to facilitate the flow of thefluid into and out of the spaces between them.

The diameter and spacing of the discs 27 may be varied to suit fluids ofvaried viscosity. The greater theviscosity thegreater the spacing anddiameter of the discs.

Similarly the angular inclination of the impeller shafts 19 and 20 maybe adjusted by swiveling the lower yoke bar 14 in relation to the upperyoke bar 12.

An alternate form of the device is illustrated in Figures 4 and 5wherein the discs 31 are conical in shape. Each disc 31 has a flat seatportion 32 at its apex which bears against the spacer collars 28. Theconical surfaces are set at an angle of between 15 and 20. These collarsand discs are also mounted free on the impeller shafts as are the flatdiscs 27. It has been found that in some applications, such conicallyshaped, freely rotating discs will effect a better mixing action.

The device as described provides a mixing head having an eccentriceffect, while at the same time being perfectly balanced with relation toits center of rotation. Furtherand tacky compounds.

It willfnow be clean-thatthere is provided a 'devicr which accomplishesthe objectives heretofore set forth While'the invention hasbeendisclosed in its preferred form; it is to be understood that thespecific embodiment of fiuid materials to be'mixed, comprising in combiiia tion, a drive shaft having a' yoke mounted thereon including twospaced impeller shafts mounted laterally, each side of the drive shaft,.at an angle liter te and ash other, and a plurality of coaxiaLpaiallel.fahdzfumformly spaced conical disc impeller.lefnents mounted oneach of said impeller shaftsgeach ofisaid cohicaldisc eleinents beingindependently free to'rotateion its ir'npelle'r" shaft.

2. Mixing apparatus adaptedto be immersedLin-a body of fluid materialsto be mixed, comprising' in'combination, a drive shaft having a yokemounted thereori'including two spaced impeller shafts mountedlaterallyo'f each side of the drive shaft, at'an angle theretoandtofeach other, and means for varying the angular disposition of theimpeller shafts between adjusted positions, and a pluralityof' coaxialparallel and uniformly spaced fiat disc impeller elements mounted oneach of said impeller shafts; each of said disc elements beingindependently free to rotate on its impeller shaft. v

3. Mixing apparatus adapted to -be immersed in a body of fluid materialsto be miq ed cgmprising in combination a drive shaft having ayoke-mounted thereon including two spaced impeller shafts mountedlaterally of each side of the drive shaft,,at an angle thereto and toeach other, and means for varying the angular disposition of theimpeller shafts between adjusted 'positions and. a plurality of coaxial,parallel and uniformly spaced conical disc impeller elements mounted oneach of said impeller shafts; each of said conical, disc elements beingindependently free to rotate on its impeller shaft. 1

References Cited in the file of this patent 5- UNITED STATES PATENTS"

